The inventive concepts disclosed herein generally relate to the field of load sensing and monitoring secondary load paths. Specifically, the inventive concepts relate to load sensing and monitoring secondary load paths in an aircraft.
In modern avionic systems, redundant systems are in place for critical systems within an aircraft. These redundant systems can be electrical, mechanical, etc. With regards to modern aircraft systems, a number of secondary load paths relating to mechanical systems within the aircraft may exist. These secondary load paths are required to remain unloaded during normal operation of the aircraft, and only be loaded if the primary system fails, in order to prevent strain or wear on the secondary load paths from accumulating over time. Example aircraft components that require secondary load paths can include stabilizing actuators, wing struts, airfoil linkages, etc. Accordingly, these secondary load paths must be tested and verified to be unloaded during normal operation of the aircraft.
Currently, these secondary load paths are tested using multiple strain gauges installed along a primary and a secondary load path. These strain gauges may monitor a tensioned load on one or more secondary load paths. The strain gauges can then provide the load data to users. In some instances, the strain gauges can be in communication with a central processing station, which may collect the strain gauge data from multiple strain gauges for processing. Further, the strain gauges are often adhered to a surface of a primary or a secondary load path component. This can often permanently attach the strain gauge to the surface of the secondary load path component, thereby preventing the strain gauge from being removed without damaging the strain gauge, and rendering it inoperable for future use. This results in substantially high costs to perform required testing, as strain gauges are often high cost items. Further, the secondary load path component may need to be modified to accept the strain gauge, resulting in additional cost. Additionally, installation of the strain gauges onto the secondary load paths generally requires skilled personnel. Once installed, strain gauges often require calibration to determine the highest fidelity gauge response at various load steps across the entire load spectrum. Further, this calibration is often verified multiple times to determine strain gauge output repeatability, which further increases the cost associated with using strain gauges to verify that no load is placed on the secondary load path components within an aircraft.
Additionally, strain gauges are often susceptible to damage from handling and installation due to the fine wiring and connection terminals within the strain gauges. This can further increase the risk of replacement and recalibration of strain gauges, which further increases the cost associated with using strain gauges to monitor for loading on secondary load paths.
Accordingly, current systems and methods monitoring for a load placed on a secondary load path can be complex and expensive due to the cost and number of strain gauges required to complete the testing, as well as due to the modifications to the components and installation of the strain gauges. Thus, a simple and cost-effective method of monitoring for the presence of a load on a secondary load path may be desirous.